Chair backrest



FIG. 1 is a front perspective view of a chair backrest in a first embodiment;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is right side view thereof;

FIG. 7 is a top plan view thereof; and

FIG. 8 is a bottom view thereof.

FIG. 9 is a front perspective view of the chair backrest in a second embodiment;

FIG. 10 is a rear perspective view thereof;

FIG. 11 is a front view thereof;

FIG. 12 is a rear view thereof;

FIG. 13 is a left side view thereof;

FIG. 14 is right side view thereof;

FIG. 15 is a top plan view thereof; and,

FIG. 16 is a bottom view thereof.

The broken line showing of the chair backrest is for the purpose of illustrating environmental structure and forms no part of the claimed design. 

CLAIM The ornamental design for a chair backrest, as shown and described. 